Many electrical switches are of the type which encounter "overtravel" after the state of the electrical connection of the switch has been altered. In most instances, an actuator is employed to operate the switch. The actuator and its associated components usually go through a "pretravel" before electrical connection is made or the switch state is altered, which sometimes is termed the "operating point". The actuator and/or its associated components then go through an overtravel condition of movement after the operating point. Upon release of the actuator, reverse movement usually takes place and a "release point" occurs when the electrical connection and its associated circuit is transferred back to its original state. This usually occurs sometime during return movement of the actuator.
In most prior art switches, the return travel of the actuator prior to reaching the release point is the same as the overtravel of the switch. In other words, there is a fixed operating point and a fixed release point for any given switch which do not vary. Release of the actuator does not instantaneously transfer the circuit back to its original state.
In copending, application Ser. No. 091,384, filed Aug. 27, 1987, (now U.S. Pat. No. 4,778,960) which is a continuation-in-part of commonly assigned, earlier filed application Ser. No. 903,760, filed Sept. 4, 1986, a unique floating, operating and release point switch is disclosed in which new operating and release points may be effected with each actuation and release of the actuator. This allows the switch to utilize a movement differential to actuate or deactuate the circuit rather than cause actuation or deactuation at respective absolute positions. The switch will revert to its initial state immediately upon initiation of the actuator return movement. In other words, any overtravel distance traveled upon actuation from the initial state of the switch is not traveled preliminary to reversion of the switch back to its initial state.
The above novel concept is accomplished by providing a friction piece normally frictionally grasping a plunger so as to be movable therewith and relatively movable with respect to the plunger when movement of the friction piece is resisted. The friction piece is oriented with respect to a mounting means such that movement of the friction piece may effect relative movement between relatively movable switch contacts as a result of the frictional grasping. Therefore, the plunger through the friction piece, effectively moves the switch contacts to transfer a circuit, allows the plunger to overtravel the operating point, and effectively moves the contacts back to the original state, as a result of the friction, immediately upon release of the plunger.
While the aforesaid prior floating, operating and release point switch has proven quite effective and useful, the present invention is directed to an improvement in order to reduce the wear on the frictional components.